(a) Technical Field
The present disclosure relates to a silicon hose and a method for manufacturing the same. More particularly, it relates to a silicon hose for use in a coolant loop of a fuel cell system and a method for manufacturing the same.
(b) Background Art
A fuel cell system applied to a hydrogen fuel cell vehicle comprises a fuel cell stack for generating electricity by an electrochemical reaction of reactant gases, a hydrogen supply system for supplying hydrogen as a fuel to the fuel cell stack, an air supply system for supplying oxygen-containing air as an oxidant required for the electrochemical reaction in the fuel cell stack, a thermal management system for removing reaction heat from the fuel cell stack to the outside of the fuel cell system, controlling operation temperature of the fuel cell stack, and performing water management function, and a system controller for controlling the overall operation of the fuel cell system.
In the above configuration, the fuel cell stack generates electrical energy by the electrochemical reaction of hydrogen and oxygen as reactant gases and discharges heat and water as by-products of the reaction. A system for cooling the fuel cell system to prevent the temperature rise of the fuel cell stack is required in the fuel cell system.
In a typical fuel cell system for a vehicle, a water cooling system for circulating water through a coolant channel in the fuel cell stack is used to cool the fuel cell stack, thus maintaining the fuel cell stack at an optimal temperature.
A configuration of the cooling system of the fuel cell vehicle is shown in FIG. 1. As shown in the figure, the cooling system comprises a coolant line 3 disposed between a fuel cell stack 1 and a radiator 2 to circulate a coolant, a bypass line 4 and a valve 5 for bypassing the coolant so as not to pass through the radiator 2, and a water pump 6 for pumping the coolant from the coolant line 3.
The pipes constituting the coolant loop of the fuel cell system (vehicle) should be made from a certain material that releases no or less ions because released ions would cause a serious problem that the electricity generated from the fuel cell stack may flow through the coolant, which may cause a serious danger to the driver and passengers.
To prevent this problem, the electrical conductivity of the coolant is measured in the fuel cell vehicle at all times, and a control logic for shutting down the fuel cell system when the electrical conductivity is increased to a predetermined level is employed. Moreover, a deionizer 7 may be provided in the coolant loop to maintain the ion conductivity of the coolant below a predetermined level.
Materials that can be used to make such pipes include, for example, SUS316L, Teflon, Al 3003, Food-Grade silicon, and the like.
FIG. 2 shows a configuration of a coolant pipe for applied to a fuel cell vehicle, in which a silicon hose 11 for preventing ion release is used.
A silicon hose does not cause ion release problem, is light in weight, and is inexpensive. It is, however, impossible to mount to the silicon hose a variety of sensors for measuring the temperature, pressure, and ion conductivity of the coolant; accordingly, a metal part 12 such as SUS316L is used where the sensor is mounted. More particularly, for example, as shown in FIG. 2, a sensor port 20 is welded and fixed to the manifold 12 formed of SUS3161L or to a predetermined position of the pipe, and the sensor is inserted and fitted into the fixed sensor port 20.
However, when a metal part is used, the overall weight and manufacturing cost are increased, which reduces the fuel efficiency and makes mass production difficult.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.